During the 1880s, the transition from outhouses to indoor plumbing was moving at a rapid pace, starting with better homes and commercial buildings. The burgeoning market for indoor plumbing spurred some gasfitters and other metal workers to specialize in this work.

The true craftsmen sought ways to distinguish those who knew what they were doing from those who didn’t. In 1882, a group of these new tradesmen in New York City banded together to form the Master Plumbers Association of New York. Shortly afterward, a like-minded group joined forces in Brooklyn.

In 1883, the 125 members of the New York group formed the National Association of Master Plumbers (NAMP) to provide the public with a complete, safe and sanitary plumbing system. NAMP was the forerunner of the National Association of Plumbing-Heating-Cooling Contractors (NAPHCC), which later became the Plumbing-Heating-Cooling Contractors–National Association (PHCC).